Azure Key Vault API Authentication

Good Morning PowerShellers! I am writing an application to connect to a SSH server and authenticate using a private key. Due to the security of the data that I am passing, I need to make sure the key storage is not on the server that is making the connection. I am planning on using the Azure Key Vault to store the keys. There is a REST API, and I can write the API calls with no issue. The question I have is in “registering” PowerShell and service account from my Azure based server so that it has an access token to use when connecting to the API. The documentation is not very clear on this part. Thanks in advance.